Huntington's disease

Huntington's disease is a rare, inherited disease that causes the progressive breakdown (degeneration) of nerve cells in the brain. Huntington's disease has a wide impact on a person's functional abilities and usually results in movement, thinking (cognitive) and psychiatric disorders.

Huntington's disease symptoms can develop at any time, but they often first appear when people are in their 30s or 40s. If the condition develops before age 20, it's called juvenile Huntington's disease. When Huntington's develops early, symptoms are somewhat different and the disease may progress faster.

Medications are available to help manage the symptoms of Huntington's disease. But treatments can't prevent the physical, mental and behavioral decline associated with the condition.

Symptoms

Huntington's disease usually causes movement, cognitive and psychiatric disorders with a wide spectrum of signs and symptoms. Which symptoms appear first varies greatly from person to person. Some symptoms appear more dominant or have a greater effect on functional ability, but that can change throughout the course of the disease.

Movement disorders

The movement disorders associated with Huntington's disease can include both involuntary movement problems and impairments in voluntary movements, such as:

• Involuntary jerking or writhing movements (chorea)
• Muscle problems, such as rigidity or muscle contracture (dystonia)
• Slow or unusual eye movements
• Impaired gait, posture and balance
• Difficulty with speech or swallowing

Impairments in voluntary movements — rather than involuntary movements — may have a greater impact on a person's ability to work, perform daily activities, communicate and remain independent.

Cognitive disorders

Cognitive impairments often associated with Huntington's disease include:

• Difficulty organizing, prioritizing or focusing on tasks
• Lack of flexibility or the tendency to get stuck on a thought, behavior or action (perseveration)
• Lack of impulse control that can result in outbursts, acting without thinking and sexual promiscuity
• Lack of awareness of one's own behaviors and abilities
• Slowness in processing thoughts or ''finding'' words
• Difficulty in learning new information

Psychiatric disorders

The most common psychiatric disorder associated with Huntington's disease is depression. This isn't simply a reaction to receiving a diagnosis of Huntington's disease. Instead, depression appears to occur because of injury to the brain and subsequent changes in brain function. Signs and symptoms may include:

• Feelings of irritability, sadness or apathy
• Social withdrawal
• Insomnia
• Fatigue and loss of energy
• Frequent thoughts of death, dying or suicide

Other common psychiatric disorders include:

• Obsessive-compulsive disorder, a condition marked by recurrent, intrusive thoughts and repetitive behaviors
• Mania, which can cause elevated mood, overactivity, impulsive behavior and inflated self-esteem
• Bipolar disorder, a condition with alternating episodes of depression and mania

In addition to the above disorders, weight loss is common in people with Huntington's disease, especially as the disease progresses.

Symptoms of juvenile Huntington's disease

The start and progression of Huntington's disease in younger people may be slightly different from that in adults. Problems that often present early in the course of the disease include:

Behavioral changes

• Difficulty paying attention
• Rapid, significant drop in overall school performance
• Behavioral problems

Physical changes

• Contracted and rigid muscles that affect gait (especially in young children)
• Tremors or slight involuntary movements
• Frequent falls or clumsiness
• Seizures

When to see a doctor

See your health care provider if you notice changes in your movements, emotional state or mental ability. The signs and symptoms of Huntington's disease can be caused by a number of different conditions. Therefore, it's important to get a prompt, thorough diagnosis.

Causes

Huntington's disease is caused by an inherited difference in a single gene. Huntington's disease is an autosomal dominant disorder, which means that a person needs only one copy of the nontypical gene to develop the disorder.

With the exception of genes on the sex chromosomes, a person inherits two copies of every gene — one copy from each parent. A parent with a nontypical gene could pass along the nontypical copy of the gene or the healthy copy. Each child in the family, therefore, has a 50% chance of inheriting the gene that causes the genetic disorder.

Complications

After Huntington's disease starts, a person's functional abilities gradually worsen over time. The rate of disease progression and duration varies. The time from the first symptoms to death is often about 10 to 30 years. Juvenile Huntington's disease usually results in death within 10 years after symptoms develop.

The clinical depression associated with Huntington's disease may increase the risk of suicide. Some research suggests that the greatest risk of suicide occurs before a diagnosis is made and in the middle stages of the disease when a person starts to lose independence.

Eventually, a person with Huntington's disease requires help with all activities of daily living and care. Late in the disease, the person will likely be confined to a bed and unable to speak. Someone with Huntington's disease is generally able to understand language and has an awareness of family and friends, though some won't recognize family members.

Common causes of death include:

• Pneumonia or other infections
• Injuries related to falls
• Complications related to the inability to swallow

Prevention

People with a known family history of Huntington's disease are understandably concerned about whether they may pass the Huntington gene on to their children. These people may consider genetic testing and family planning options.

If an at-risk parent is considering genetic testing, it can be helpful to meet with a genetic counselor. A genetic counselor will discuss the potential risks of a positive test result, which would indicate that the parent will develop the disease. Also, couples will need to make additional choices about whether to have children or to consider alternatives, such as prenatal testing for the gene or in vitro fertilization with donor sperm or eggs.

Another option for couples is in vitro fertilization and preimplantation genetic diagnosis. In this process, eggs are removed from the ovaries and fertilized with the father's sperm in a laboratory. The embryos are tested for presence of the Huntington gene, and only those testing negative for the Huntington gene are implanted in the mother's uterus.

Diagnosis

A preliminary diagnosis of Huntington's disease is based primarily on your answers to questions, a general physical exam, a review of your family medical history, and neurological and psychiatric examinations.

Neurological examination

The neurologist will ask you questions and conduct relatively simple tests of your:

• Motor symptoms, such as reflexes, muscle strength and balance
• Sensory symptoms, including sense of touch, vision and hearing
• Psychiatric symptoms, such as mood and mental status

Neuropsychological testing

The neurologist may also perform standardized tests to check your:

• Memory
• Reasoning
• Mental agility
• Language skills
• Spatial reasoning

Psychiatric evaluation

You'll likely be referred to a psychiatrist for an examination to look for a number of factors that could contribute to your diagnosis, including:

• Emotional state
• Patterns of behaviors
• Quality of judgment
• Coping skills
• Signs of disordered thinking
• Evidence of substance abuse

Brain-imaging and function tests

Your provider may order brain-imaging tests for assessing the structure or function of the brain. The imaging technologies may include MRI or CT scans that show detailed images of the brain.

These images may reveal changes in the brain in areas affected by Huntington's disease. These changes may not show up early in the course of the disease. These tests can also be used to rule out other conditions that may be causing symptoms.

Genetic counseling and testing

If symptoms strongly suggest Huntington's disease, your provider may recommend a genetic test for the nontypical gene.

This test can confirm the diagnosis. It may also be valuable if there's no known family history of Huntington's disease or if no other family member's diagnosis was confirmed with a genetic test. But the test won't provide information that might help determine a treatment plan.

Before having such a test, the genetic counselor will explain the benefits and drawbacks of learning test results. The genetic counselor can also answer questions about the inheritance patterns of Huntington's disease.

Predictive genetic test

A genetic test can be given if you have a family history of the disease but don't have symptoms. This is called predictive testing. The test can't tell you when the disease will begin or what symptoms will appear first.

Some people may have the test because they find not knowing to be more stressful. Others may want to take the test before having children.

Risks may include problems with insurability or future employment and the stresses of facing a fatal disease. In principle, federal laws exist that make it illegal to use genetic testing information to discriminate against people with genetic diseases.

These tests are only performed after consultation with a genetic counselor.

Treatment

No treatments can alter the course of Huntington's disease. But medications can lessen some symptoms of movement and psychiatric disorders. And multiple interventions can help a person adapt to changes in abilities for a certain amount of time.

Medications will likely evolve over the course of the disease, depending on overall treatment goals. Also, drugs that treat some symptoms may result in side effects that worsen other symptoms. Treatment goals will be regularly reviewed and updated.

Medications for movement disorders

Drugs to treat movement disorders include the following:

• Drugs to control movement include tetrabenazine (Xenazine) and deutetrabenazine (Austedo), which have been specifically approved by the Food and Drug Administration to suppress the involuntary jerking and writhing movements (chorea) associated with Huntington's disease. These drugs don't have any effect on the progression of the disease, however. Possible side effects include drowsiness, restlessness, and the risk of worsening or triggering depression or other psychiatric conditions.

• Antipsychotic drugs, such as haloperidol and fluphenazine, have a side effect of suppressing movements. Therefore, they may be beneficial in treating chorea. However, these drugs may worsen involuntary contractions (dystonia), restlessness and drowsiness.

  Other drugs, such as olanzapine (Zyprexa) and aripiprazole (Abilify), may have fewer side effects but still should be used with caution, as they may also worsen symptoms.

• Other medications that may help suppress chorea include amantadine (Gocovri, Osmolex ER), levetiracetam (Keppra, Elepsia XR, Spritam) and clonazepam (Klonopin). However, side effects may limit their use.

Medications for psychiatric disorders

Medications to treat psychiatric disorders will vary depending on the disorders and symptoms. Possible treatments include the following:

• Antidepressants include such drugs as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac) and sertraline (Zoloft). These drugs may also have some effect on treating obsessive-compulsive disorder. Side effects may include nausea, diarrhea, drowsiness and low blood pressure.
• Antipsychotic drugs such as quetiapine (Seroquel) and olanzapine (Zyprexa) may suppress violent outbursts, agitation, and other symptoms of mood disorders or psychosis. However, these drugs may cause different movement disorders themselves.
• Mood-stabilizing drugs that can help prevent the highs and lows associated with bipolar disorder include anticonvulsants, such as divalproex (Depakote), carbamazepine (Tegretol, Carbatrol, Epitol, others) and lamotrigine (Lamictal).

Psychotherapy

A psychotherapist — a psychiatrist, psychologist or clinical social worker — can provide talk therapy to help with behavioral problems, develop coping strategies, manage expectations during progression of the disease and help family members communicate with each other.

Speech therapy

Huntington's disease can significantly impair control of muscles of the mouth and throat that are essential for speech, eating and swallowing. A speech therapist can help improve your ability to speak clearly or teach you to use communication devices — such as a board covered with pictures of everyday items and activities. Speech therapists can also address difficulties with muscles used in eating and swallowing.

Physical therapy

A physical therapist can teach you appropriate and safe exercises that enhance strength, flexibility, balance and coordination. These exercises can help maintain mobility as long as possible and may reduce the risk of falls.

Instruction on appropriate posture and the use of supports to improve posture may help lessen the severity of some movement problems.

When the use of a walker or wheelchair is required, the physical therapist can provide instruction on appropriate use of the device and posture. Also, exercise regimens can be adapted to suit the new level of mobility.

Occupational therapy

An occupational therapist can assist the person with Huntington's disease, family members and caregivers on the use of assistive devices that improve functional abilities. These strategies may include:

• Handrails at home
• Assistive devices for activities such as bathing and dressing
• Eating and drinking utensils adapted for people with limited fine motor skills

Lifestyle and home remedies

Managing Huntington's disease affects the person with the disorder, family members and other in-home caregivers. As the disease progresses, the person will become more dependent on caregivers. Several issues will need to be addressed, and the ways to cope with them will change over time.

Eating and nutrition

Factors regarding eating and nutrition include the following:

• Difficulty maintaining a healthy body weight. This may be caused by difficulty eating, higher caloric needs due to physical exertion or unknown metabolic problems. To get adequate nutrition, you may need to eat more than three meals a day or use dietary supplements.
• Difficulty with chewing, swallowing and fine motor skills. These problems can limit the amount of food you eat and increase the risk of choking. It may help to remove distractions during a meal and select foods that are easier to eat. Utensils designed for people with limited fine motor skills and covered cups with straws or drinking spouts also can help.

Eventually, a person with Huntington's disease will need assistance with eating and drinking.

Managing cognitive and psychiatric disorders

Family and caregivers can help create an environment that may help a person with Huntington's disease avoid stressors and manage cognitive and behavioral challenges. These strategies include:

• Using calendars and schedules to help keep a regular routine
• Initiating tasks with reminders or assistance
• Prioritizing or organizing work or activities
• Breaking down tasks into manageable steps
• Creating an environment that is as calm, simple and structured as possible
• Identifying and avoiding stressors that can trigger outbursts, irritability, depression or other problems
• For school-age children or adolescents, consulting with school staff to develop an appropriate individual education plan
• Providing opportunities for the person to maintain social interactions and friendships as much as possible

Coping and support

A number of strategies may help people with Huntington's disease and their families cope with the challenges of the disease.

Support services

Support services for people with Huntington's disease and families include the following:

• Nonprofit agencies, such as the Huntington's Disease Society of America, provide caregiver education, referrals to outside services, and support groups for people with the disease and caregivers.
• Local and state health or social service agencies may provide daytime care for people with the disease, meal assistance programs or respite for caregivers.

Planning for residential and end-of-life care

Because Huntington's disease causes the progressive loss of function and death, it's important to anticipate care that will be needed in the advanced stages of the disease and near the end of life. Early discussions about this type of care enable the person with Huntington's disease to be engaged in these decisions and to share what they want from their care.

Creating legal documents that define end-of-life care can be beneficial to everyone. They empower the person with the disease, and they may help family members avoid conflict late in the disease progression. Your provider can offer advice on the benefits and drawbacks of care options at a time when all choices can be carefully considered.

Matters that may need to be addressed include:

• Care facilities. Care in the advanced stages of the disease will likely require in-home nursing care or care in an assisted living facility or nursing home.
• Hospice care. Hospice services provide care at the end of life that helps a person approach death with as little discomfort as possible. This care also provides support and education to family members to help them understand the process of dying.
• Living wills. Living wills are legal documents that enable a person to spell out care preferences when it isn't possible to make decisions. For example, these directions might indicate whether or not the person wants life-sustaining interventions or aggressive treatment of an infection.
• Advance directives. These legal documents enable you to identify one or more people to make decisions on your behalf. You may create an advance directive for medical decisions or financial matters.

Preparing for an appointment

If you have any signs or symptoms associated with Huntington's disease, you'll likely be referred to a neurologist after an initial visit to your provider.

A review of your symptoms, mental state, medical history and family medical history can all be important in the clinical assessment of a potential neurological disorder.

What you can do

Before your appointment, make a list that includes the following:

• Signs or symptoms — or any changes from what is normal for you — that may be causing concern
• Recent changes or stresses in your life
• All medications — including drugs available without a prescription and dietary supplements — and doses you take
• Family history of Huntington's disease or other disorders that may cause movement disorders or psychiatric conditions

You may want a family member or friend to accompany you to your appointment. This person can provide support and offer a different perspective on the effect of symptoms on your functional abilities.

What to expect from your doctor

Your provider is likely to ask you a number of questions, including the following:

• When did you begin experiencing symptoms?
• Have your symptoms been continuous or intermittent?
• Has anyone in your family ever been diagnosed with Huntington's disease?
• Has anyone in your family been diagnosed with another movement disorder or psychiatric disorder?
• Are you having trouble performing work, schoolwork or daily tasks?
• Has anyone in your family died young?
• Is anyone in your family in a nursing home?
• Is anyone in your family fidgety or moving all the time?
• Have you noticed a change in your general mood?
• Do you feel sad all of the time?
• Have you ever thought about suicide?

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